Actually, busy detection, regardless of its efficacy has a problem. I pointed this out in my comments to the FCC on RM-11306.
If the originating station 'hears' a station it won't transmit. But what happens when the station turns it over to the other party that the originating station can't hear. Does it immediately begin transmitting, wait one minute, two minutes, etc. It may very well time out and begin transmitting thus interfering with an ongoing conversation. To be sure of not interfering, both the originating (manual or automatic) and the automatic station must communicate in some fashion to insure that IF either station hears a signal, neither sends. Jim WA0LYK --- In digitalradio@yahoogroups.com, "Dave Bernstein" <[EMAIL PROTECTED]> wrote: > > Yes, SCAMP's busy detectors exceeded everyone's expectations. > > Some SCS modems also include a busy frequency detector, but to my > knowledge no automatic station operation software exploits them. > > The issue, as illustrated in John's scenario, is that the remote > station activating the automatic station has no idea what can be > heard on the frequency at the automatic station's QTH when the two > are separated by any significant distance. Thus the remote operator > cannot know that the frequency is truly clear without help from a > person or circuit at the automatic station's QTH. > > 73, > > Dave, AA6YQ > > > > --- In digitalradio@yahoogroups.com, doc <kd4e@> wrote: > > > > Hasn't SCAMP already successfully demonstrated the technology > > for checking multiple modes prior to transmission? > > > > Also, just because one cannot detect 1/2 of a QSO does > > not mean that one may not detect the other 1/2. > > > > If one truly cannot detect either side (with reasonable > > receive sensitivity and antenna gain employed) then one's > > legal transmission (only the minimum power necessary to > > establish and maintain communications) will not be capable > > of QRMing the existing QSO. > > > > If you cannot hear them they should not be able to hear > > you -- unless you are running an "alligator" station > > (transmit side not balanced with the receive side). > > > > IMHO, YMMV ... 73, doc kd4e > > > > > Lets try the guy 150 miles from you well within your > > > ring of silence (you can't copy each other if you had to) > > > listens to the frenquncy (unable to ask if the frequency > > > is in use on every mode known to man) hears nothing. > > > brings up the auto station and in doing so QRM's a QSO > > > on the same frequency that he did not hear. > > > > > > Now as I see it that is not the fault of the auto station. > > > But I know you are going to say that the auto station > > > *should* be able to tell if it was in use. And that is getting > > > real old with me. > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
